Cooling fan static

[RetArmy]

I have an MIT-100 intercom unit that picks up static noise when the cooling fan kicks in. I have an accessory plug on the right side fairing I hooked up directly to the battery and noticed the noise when the fan kicks in. I am going to install a wiring harness and hook up a CB power supply, the power outlet for the MIT-100 power supply and a Garmin 2610 GPS power supply to it. Anyone know if this will eliminate the noise or do I need some kind of noise suppressor inline to eliminate the problem? If so, where do I splice the suppressor in at? Any help is appreciated.

[crazykz]

It would be my recommendation to play around with the MIT-100 a bit to see if you can eliminate the noise before hooking everything else up.

Where did you place the MIT-100? Since the MIT-100 is your intercom you may want to consider powering it from the battery as close as you can. I put a fuseblock in the tail section that uses a relay for switched power. It then switches 12V from the battery.

My guess is that if you're picking up fan noise you are getting power for the MIT-100 from the quartet harness but that's a guess. Let me know your setup, pics if possible, and I'll let you know where I think the issue is.

I may even be able to come down and take a look if I get some time.

Curt

[BentAero]

CurtWonKanobe: I have the same problem James does. I'm getting power from a Blue Sea Power Box that's in the 'tool kit' hole, which is hooked to the battery, so essentially, I'm getting power straight from the battery for sake of conversation. When the fan kicks on, it's downright deafening in my ears.

Anyway, please come down and fix mine too. I'll take you on the 'backroads' tour! ;)

[georgeorge]

If I was having that problem, I would try a noise suppressor like what is available here:
http://www.buyreliant.com/caudio/noise.htm
I would put one of these inline with the positive lead to the MIT.

[crazykz]

An inline filter is a good suggestion but I'm puzzled how both of these guys are getting the same thing. They could be two different issues and power is a good place to start. Here are links to two other ones that seem to come up here.

N-500 from http://www.davidnavone.com/filters.html (My choice and John from Mix-It Products sells it also)

S-15A Power Filter from http://www.crutchfield.com/S-pp5DWl9RLWW/cgi-bin/ProdView.asp?g=181150&I=003S15A&search=filter

Now what I still haven't seen is where is the MIT-100 located and where did you run your cables. If you got near the fan motor or the power to the fan I could see a cable picking up the RF. Basically it usually boils down to where the cables are run and if they are protected.

The power filter is a good place to start that's quick and easy to try.

Curt

[Putt]

If you can get to the fan leads, you can take a .01 disc capacitor
and go from both fan leads to chassis ground... the arcing from the
fan brushes is creating RF and "probably" coming back up thru the fan
leads.. I would try an inline noise supressor first...


Putt...

[Marshal_Mercer]

James/Gary:

If you are connected directly to the battery for power, you should be RFI/EMI "clean". However, if you have any of your intercom or other accessory's wiring on or very near the right-rear (as you sit on the seat) of your bikes tail section (under the passenger seat) you will pick up RFI and EMI exactly as you described. There are two simple solutions for this: move the wires to the left side of the tail section, then take a two-to-three foot section of electrical wire and coil it several times into a 6" loop. Place the loop over your intercom wires. The second solution is to place a "ground-loop isolator" as has been described in this Forum (search on "ground-loop") between your voice input and output lines; there is probably a 2.5 or 3mm jack to connect through.

Good luck on this. I know that it can be a real pain in the ears when the fan comes on.

Marshal

[RetArmy]

Thanks guys for all of the great info. I was powering the MIT-100 from a panel mounted plug wired directly to the battery. I also used a battery powered CB which was connected to the MIT using the cable supplied with the MIT at the same time when the noise started. Could the CB be the culprit and it is picking up the static? I will be converting over to the quartet harness when it gets warm enough to work in the garage. I will be connecting power for a Garmin 2610 GPS, a CSS-100 cruise control power and the panel mounted plug to the outlets of the harness. I keep the MIT unit in a tank bag and want to easily remove it by using the panel plug for power so it can be removed. I hope this makes sense. Where would I install the noise filter for best efficiency? Would I put it between the bike harness and 9 pin connector of the wiring harness? Do I need one for each device?

[crazykz]

Thanks guys for all of the great info. I was powering the MIT-100 from a panel mounted plug wired directly to the battery. I also used a battery powered CB which was connected to the MIT using the cable supplied with the MIT at the same time when the noise started. Could the CB be the culprit and it is picking up the static?

It very well could be and a CB has a double issue in that you can get a ground loop through the mic ground as well as the headset connection. I'm still trying to figure this one out myself.

I will be converting over to the quartet harness when it gets warm enough to work in the garage. I will be connecting power for a Garmin 2610 GPS, a CSS-100 cruise control power and the panel mounted plug to the outlets of the harness. I keep the MIT unit in a tank bag and want to easily remove it by using the panel plug for power so it can be removed. I hope this makes sense. Where would I install the noise filter for best efficiency?

Since you're going to move everything around anyway you may want to wait and see if this issue continues after you get everything situated. You would want to locate the filter as close to what you're trying to power as possible since that will filter any noise picked up along the way but before it gets to your device.

Would I put it between the bike harness and 9 pin connector of the wiring harness?

That would be tough to do and I don't think that's where you would necessarily need it. I would say to try and put it in before the plug you will use for powering the MIT. You could put it in the fairing if your power plug will be on the right fairing.

Do I need one for each device?

Probably not but you may need to play around with it to find the best spot. Adding a capacitor across the fan leads might also be a good thing to try to see if eliminates the noise.

Curt

[RetArmy]

OK. I will wait until everything is hooked up before I do anything. I want to thank all of you very much for all of the input I received. What a great site and great people.

[BentAero]

James/Gary:

"There are two simple solutions for this: move the wires to the left side of the tail section, then take a two-to-three foot section of electrical wire and coil it several times into a 6" loop. Place the loop over your intercom wires."
Marshal

Marshal:

Let's pretend that I'm even dumber than I actually am. Are you talking about taking the power wires themselves and extending them 2 or 3 feet and coiling them (over itself), or a separate piece of wire that is not connected to anything, i.e. just "laying" there :confused:

[Fireball18]

I had a similar problem with my S&M CB on my '03 ST. The J&M unit is a CB, weather channel, aux. audio component all in one. I found that if I had the squelch turned too low on the CB I would get cooling fan interference. Turning the squelch up a tad cured that. It was mostly a problem when at a stop or very slow riding, as in a parking lot.

Both the Electrical Connection and Sierra Electronics sell a noise suppressor that plugs inline between the aux. music source (i.e., and mp3 player, etc.) and the audio amp section of the radio. I don't believe you should experience any ground looping effect if your CB is battery powered, though, because it's not connected to the bike's electrical system. You migh try running your intercom's power cables through some shielding and ground it at either end. Also, take care not to run power wires anywhere near the bike's ignition coils. That'll drive you crazy! Same for the wires going to the cooling fans. The .01 capacitor idea is a great one for the fan's wire connections.

[crazykz]

I may have missed that you are powering the CB from battery. If that's the case then I think you're picking up RF but if it was just a squelch issue you would have noticed that by now. I won't assume anything anymore. :o:

Curt

[Marshal_Mercer]

Marshal:

Let's pretend that I'm even dumber than I actually am. Are you talking about taking the power wires themselves and extending them 2 or 3 feet and coiling them (over itself), or a separate piece of wire that is not connected to anything, i.e. just "laying" there :confused:
No need to pretend. :D

No, I'm not suggesting that the AutoCom's wires should be extended. I meant that one or two pieces of wire, not attached to anything, could be used as an RFI shield.

Here's the logic behind this: When an electrically conductive wire is coiled it becomes more inductive. That is, it acts more like a magnet than it normally would. By placing one or two coiled wires over the AutoCom’s cables you have created a low-level radio frequency interference (RFI) shield, protecting the cables/wire, to some degree, from RFI-leaking electrical wires in that area. Will it work as well as using shielded wires in the first place? No. But who wants to go to that expense when a nearly free solution exists? Try it -- you'll be sold.

Cheers,

Marshal
Snap, krackle, and pop-free for over 1 day

[crazykz]

Another way to do that is to ground one side of the coiled wire so any interference it does pick up is shunted to ground. A straight wire with no ground is an antenna.

Curt

[Marshal_Mercer]

Another way to do that is to ground one side of the coiled wire so any interference it does pick up is shunted to ground. A straight wire with no ground is an antenna.

Curt
Right you are. Nice catch.

Marshal

[MikeP1300]

I have one (J&M CB) too. Consider for this discussion that my ignorance of things electronic eclipses Gary's by an order of magnitude. What ever that means. I have the same interferance noise problems and the coiled shielding wire sounds interesting but, unlikely (in my mind anyway) to produce anything but a real pain in the arse to install.

I've learned to live with the fan and windscreen motor noise but, the dreaded high pitch whine is what's driving me nuts. I've installed a radio shack noise supressor and tried many power sources...no noticeable improvement. I even tried an off the bike power up test with the unit hooked to the recommended tail light power with all wires strung along floor. Same noisy stuff.

Marshall/ Curt, which wires need to be coiled and how much of them? It'll be a pain, but if it works... yahoo.

The antenna has a ground to the frame and I've had the antenna adjusted using a swr meter to very close to 1. Don't ask me what that means, but I understand it's good. CB performance is not quite in the satisfactory range.

Curt, if you remember I tried one of your ground loop thingies in Arkansas. It reduced the noise, but also the stuff I wanted to hear.

Thanks guys

[Marshal_Mercer]

<snip>
.... I even tried an off the bike power up test with the unit hooked to the recommended tail light power with all wires strung along floor. Same noisy stuff.
<snip>
Why don't you try attaching your J&M system power and ground wires (+ and -) directly to a 12 volt battery's terminals, such as your bike's, with the engine shut off. Turn the system "on". If you have noise through under that circumstance, then your bike is not the problem. If no noise, start your bike with the same set up. If the sound is still clean, then your problem lies in the tail light wire attachment. If not, then I am at a loss. Maybe Curt can jump in on this.

Marshal

[MikeP1300]

Why don't you try attaching your J&M system power and ground wires (+ and -) directly to a 12 volt battery's terminals, such as your bike's, with the engine shut off. Turn the system "on". If you have noise through under that circumstance, then your bike is not the problem. If no noise, start your bike with the same set up. If the sound is still clean, then your problem lies in the tail light wire attachment. If not, then I am at a loss. Maybe Curt can jump in on this.

Marshal

Marshall:
Motor off, quiet. Motor on, noise from every power souce I could find including direct to the battery. The CB is so incredibly clear with the motor off, I can talk to truckers miles away.

The high pitched whine sounds like alternator interference. Freqency and volume increase with rpm.

[BentAero]

Resurrected this thread from the dead with the purpose of yet another question:

Several have mentioned trying to get accy power wires 'away' from the coils as far as possible. My question is where do you route them?

Going down doesn't look too good because of the exhaust pipes, and it doesn't appear that there is enough room between the tank and the air filter box to go up the center.

Any suggestions?

[RideTN]

did anyone ever answer the questions posed in post 17 of this thread? similar problem here and wonder what happened to cure it.....